1. Field of the Invention
This invention relates to a pressure sensor and, more particularly, to a pressure sensor that uses a piezoelectric-type vibrator as a pressure detection means.
2. Description of the Prior Art
A conventional piezoelectric-type pressure sensor for measuring pressure by utilizing the piezoelectric effect uses a diaphragm valve. In such a pressure sensor, the diaphragm valve is made to have a piezoelectric characteristic and a displacement of the diaphragm valve due to pressure is detected.
However, in such a conventional pressure sensor, relatively high pressure could be detected but relatively low pressure could not be detected.